In today's commercial transport industry, it is highly desirable to design aircraft configurations that yield reduced fuel burn per seat-mile, as fuel burn per seat-mile is a metric of fuel efficiency. Efficient aircraft configurations are ever more important as fuel costs increase. Aircraft aerodynamic drag and fuel burn are generally reduced as the aspect ratio of the aircraft wing increases. Similarly, operating larger aircraft, carrying more passengers and payload, are generally more efficient between two destinations than flying several trips with smaller aircraft. Thus larger aircraft and aircraft with longer wingspans tend to be more efficient. However, taxiway spacing and gate locations for most airports were established without providing adequate spacing for aircraft with the longer wingspans that can be produced with today's technology.
Thus it is advantageous to provide an aircraft that can benefit from a long wingspan in flight, while being able to reduce the wingspan while operating at an airport.